EP 1124163 A2 20010816 - Alignment using polarised light
Title (en)
Alignment using polarised light
Title (de)
Ausrichtung unter Verwendung polarisiertes Lichtes
Title (fr)
Alignement utilisant une lumière polarisée
Publication
Application
Priority
US 50011000 A 20000208
Abstract (en)
An optical alignment system used in the manufacture of semiconductor integrated circuits determines and adjusts the alignment between features which have been formed on a semiconductor wafer and features on a mask which is being projected onto the semiconductor wafer. Light which illuminates the semiconductor wafer is scattered and diffracted into a darkfield detector system. This results in the generation of electrical signals which are used to position the mask relative to the semiconductor wafer. The use of polarized light in the present system results in an increase in the magnitude of the desired signals and a decrease in the magnitude of the spurious signals. To improve the quality of the signals, the angle of polarization of the light is adjusted to a specific relationship with respect to the geometry of the alignment marks on the semiconductor wafer. <IMAGE>
IPC 1-7
IPC 8 full level
G03F 9/00 (2006.01)
CPC (source: EP US)
G03F 9/7065 (2013.01 - EP US); G03F 9/7069 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IE IT
DOCDB simple family (publication)
EP 1124163 A2 20010816; EP 1124163 A3 20050706; TW 494464 B 20020711; US 6525818 B1 20030225
DOCDB simple family (application)
EP 01103020 A 20010208; TW 90102746 A 20010515; US 50011000 A 20000208